Heat dissipation device

ABSTRACT

A heat dissipation device includes a base, first and second fin units, two heat pipes, and a fan. The first fin unit is located on the base, and the second fin unit is located on the first fin unit. Each fin unit comprises a plurality of parallel fins with a plurality of channels defined therebetween. Each fin comprises an inlet section, an outlet section and a neck section interconnecting the inlet and outlet sections. A height of the neck section reduces gradually from the inlet section to the outlet section. Each heat pipe comprises an evaporating portion connecting with the base and a condensing portion inserting into a corresponding one of the outlet sections of the first and second fin units. The fan is located above the base and mounted onto the inlet sections of the first and second fin units.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present disclosure relates to heat dissipation devices used in association with electronic components and, more particularly, to a heat dissipation device having fins with a specially designed configuration which can enhance heat dissipation efficiency thereof.

2. Description of Related Art

Computer electronic components, such as central processing units (CPUs), generate large amounts of heat during normal operation. If the heat is not properly dissipated, it can adversely affect operational stability of the electronic components and damage associated electronic devices. A heat dissipation device is often attached to a top surface of a CPU to dissipate heat therefrom.

Conventionally, a heat dissipation device includes a base and a plurality of fins arranged on the base. The fins are rectangular and parallel to each other with parallel channels defined therebetween. A cooling fan is generally located at a lateral side of the base and the fins to provide cooling air to flow through the channels of the fins, thereby increasing cooling efficiency of the heat dissipation device. However, a height of the channels is invariable, whereby the speed of the cooling air at an inlet and an outlet of the channels is invariable. The invariable speed of the cooling air, which can not accelerate to dissipate the heat absorbed by the fins, limits the heat dissipation efficiency of the heat dissipation device.

What is needed, therefore, is an improved heat dissipation device which can overcome the described disadvantages.

BRIEF DESCRIPTION OF THE DRAWINGS

Many aspects of the present apparatus can be better understood with reference to the following drawings. The components in the drawings are not necessarily drawn to scale, the emphasis instead being placed upon clearly illustrating the principles of the present apparatus. Moreover, in the drawings, like reference numerals designate corresponding parts throughout the several views.

FIG. 1 is an exploded, isometric view of a heat dissipation device in accordance with an embodiment of the disclosure, with an electronic component.

FIG. 2 is an assembled, isometric view of the heat dissipation device in FIG. 1.

FIG. 3 is a side view of the heat dissipation device in FIG. 2.

DETAILED DESCRIPTION OF THE INVENTION

Referring to FIGS. 1-2, a heat dissipation device in accordance with an embodiment of the disclosure comprises a base 10, a first fin unit 20 and a second fin units 30 arranged on the base 10, two heat pipes 40, 50 connecting the base 10 and the first and second fin units 20, 30, and a fan 60 located on the base 10 and mounted onto a front end of the first and second fin units 20, 30.

The base 10 is a substantially rectangular plate. The base 10 is made of heat conductive material such as copper or aluminum. Preferably, the base 10 is made of copper, which has a better heat conductivity than aluminum. Two parallel grooves 12 are defined in a top surface of the base 10. A bottom surface of the base 10 is for contacting an electronic component 100 such as a CPU received in an electronic system such as a computer (not shown) and mounted on a printed circuit board (not shown). Four through holes 14 are defined at four corners of the base 10.

The heat dissipation device further comprises two locking members 16 engaging with the base 10 to secure the heat dissipation device to the printed circuit board (not shown) on which the electronic component 100 is mounted, so that the base 10 can have an intimate contact with the electronic component 100. Specifically, two through holes 160 are defined in each of the locking members 16 corresponding to the through holes 14 of the base 10. Four screws 17 engage into the through holes 160, 14 to thereby combine the base 10 and the locking members 16 together. Four fasteners 18 extend through ends of the locking members 16 to secure the locking members 16 to the printed circuit board.

The first fin unit 20 is arranged on the top surface of the base 10. The second fin unit 30 is arranged on the first fin unit 20. The first and second fin units 20, 30 have the same configuration. Each of the first and second fin units 20, 30 comprises a plurality of parallel fins 22 combined together. Each fin 22 comprises a vertical main plate 220 perpendicular to the base 10 and two flanges 221 extending from bottom and top edges of the main plate 220, respectively. The flanges 221 of a fin 22 abut against the main plate 220 of an adjacent fin 22 so as to form a channel 24 between the two adjacent fins 22. The fins 22 of the first and second fin units 20, 30 are combined together by engaging structures (not labeled) formed between adjacent fins 22.

Also referring to FIG. 3, each of the main plates 220 comprises an inlet section 222, an outlet section 226, a neck section 224 interconnecting the inlet and outlet sections 222, 226, and a bent section 228 extending downwardly from a free end of the outlet section 226. A height of the inlet section 222 is larger than that of the outlet section 226. A height of the neck section 224 reduces gradually from the inlet section 222 to the outlet section 226. Specifically, the neck section 224 has a streamline shape. Preferably, the height of the inlet section 222 is 36 millimeters (mm), and the height of the outlet section 226 is 14 mm.

The fins 22 are configured as such a manner that the channels 24 defined therebetween have a variable height. That is, the height of the channels 24 at the inlet sections 222 of the fins 22 is larger than that at the outlet sections 226 of the fins 22, and the height of the channels 24 at the neck sections 224 reduces gradually from the inlet sections 222 to the outlet sections 226 of the fins 22. The channels 24 at the bent sections 228 are slantwise to a horizontal line and oriented downwardly to the printed circuit board. A hole 223 is defined in a center of the outlet section 226 of each of the fins 22. The holes 223 of the fins 22 of the first and second fin units 20, 30 cooperate to define two passages for parts of the heat pipes 40, 50 to extend therethrough, respectively.

A configuration of the heat pipe 40 is similar to that of the heat pipe 50, and both have a substantially U shape. The heat pipe 40 comprises a horizontal evaporating portion 41, a middle portion 42 extending upwardly and slantwise from an end of the evaporating portion 41, and a condensing portion 43 extending horizontally from an end of the middle portion 42 remote from the evaporating section 41. The evaporating portion 41 and the condensing portion 43 are parallel to each other. The heat pipe 50 comprises a horizontal evaporating portion 51, a middle portion 52 extending upwardly and slantwise from an end of the evaporating portion 51, and a condensing portion 53 extending horizontally from an end of the middle portion 52 remote from the evaporating portion 51. The middle portion 52 is longer than the middle portion 42, whereby the condensing portion 53 is located above the condensing portion 43. The evaporating portions 41, 51 of the heat pipes 40, 50 are flattened and received in the two grooves 12 of the base 10. The condensing portions 43, 53 of the heat pipes 40, 50 are round and insert into the holes 223 of the first and second fin units 20, 30, respectively.

The fan 60 is mounted onto the inlet sections 222 of the first and second fin units 20, 30 by two fan holders 65.

Please referring to FIGS. 2 and 3, in assembly, the locking members 16 are engaged with the base 10. The evaporating portions 41, 51 of the heat pipes 40, 50 are respectively received in the two grooves 12 of the base 12. Tops of the evaporating portions 41, 51 and the top surface of the base 12 are coplanar. The first fin unit 20 is located on the base 12. Bottoms of the inlet sections 222 of the first fin unit 20 are attached to the base 12 and the evaporating portion 51 of the heat pipe 50. The neck sections 224, the outlet sections 226 and the bent sections 228 of the first fin unit 20 are spaced from the base 12. The condensing portion 43 of the heat pipe 40 inserts into the holes 223 of the first fin unit 20. The second fin unit 30 is located on the first fin unit 20, with bottoms of the inlet sections 222 thereof attached to tops of the inlet sections 222 of the first fin unit 20. The condensing portion 53 of the heat pipe 50 inserts into the holes 223 of the second fin unit 30. A distance between the neck sections 224 of the first and second fin units 20, 30 increases gradually from the inlet sections 222 to the outlet sections 226, since the height of the neck sections 224 reduces gradually from the inlet sections 222 to the outlet sections 226. The outlet sections 226 of the first and second fin units 20, 30 are spaced from and parallel to each other. Finally, the fan 60 is mounted onto the inlet sections 222 of the first and second fin units 20, 30 by the fan holders 65, and faces towards the channels 24.

In use, heat generated by the electronic component 100 is absorbed by the base 12 and then transferred by the heat pipes 40, 50 to the first and second fin units 20, 30, and dissipated to ambient air at last. Cooling air generated by the fan 60 can flow through the channels 24 of the first and second fin units 20, 30 to accelerate the heat dissipation of the first and second fin units 20, 30. It is noted that, since the height of the neck sections 224 of the first and second fin units 20, 30 reduces gradually, and the height of the outlet sections 226 is smaller than that of the inlet sections 222, the cooling air can speed up at the neck sections 224 and accelerate to flow out from the outlet sections 226 and the bent sections 228. Compared with the conventional heat dissipation device having the same fan 60, the cooling air can flow out of the present heat dissipation device more rapidly, due to the neck configuration of the neck sections 224 of the fin units 20, 30. Therefore, heat absorbed in the base 10 and the fin units 20, 30 can be dissipated to ambient areas more rapidly, thereby insuring that the electronic component 100 can always have a temperature within its normal working range.

Furthermore, since the bent sections 228 are oriented downwardly to the printed circuit board, cooling air flowing out therefrom can cool other heat sources mounted on the printed circuit board. Therefore, the cooling air generated by the fan 60 is well exploited. It is understood that the bent angle of the bent sections 228 can be varied from the disclosed embodiment, so long as the cooling air can be guided downwardly to cool other heat sources mounted on the printed circuit board.

Moreover, the fins 22 of the first and second fin units 20, 30 each are formed by cutting a part of a rectangular fin away therefrom to have the neck configuration. Thus, the fins 22 of the fin units 20, 30 need less material, in comparison with the conventional fin unit constructed by the rectangular fin, while have better heat dissipating effectiveness. Thus, the cost of raw materials of the heat dissipation device in accordance with the present disclosure is lower than the conventional heat dissipation device.

It is believed that the present disclosure and its advantages will be understood from the foregoing description, and it will be apparent that various changes may be made thereto without departing from the spirit and scope of the disclosure or sacrificing all of its material advantages, the examples hereinbefore described merely being preferred or exemplary embodiments of the disclosure. 

1. A heat dissipation device comprising: a base; a fin unit comprising a plurality of parallel fins arranged on the base with a plurality of channels defined therebetween, each fin comprising a main plate perpendicular to the base and two flanges bent from edges of the main plate, the main plate comprising an inlet section, an outlet section and a neck section interconnecting the inlet and outlet sections, a height of the neck section reducing gradually from the inlet section to the outlet section; and a fan located on the base and attached to the inlet sections of the fins, cooling air generated by the fan flowing into the channels via the inlet sections of the fins and accelerating to flow out from the outlet sections of the fins after the cooling air flows through the neck sections of the fins.
 2. The heat dissipation device as claimed in claim 1, wherein the main plate further comprises a bent section extending downwardly from a free end of the outlet section.
 3. The heat dissipation device as claimed in claim 1, wherein the neck section has a streamline shape.
 4. The heat dissipation device as claimed in claim 1, wherein the inlet sections of the fin unit are attached to the base and the neck sections and the outlet sections of the fin unit are spaced from the base.
 5. The heat dissipation device as claimed in claim 1, further comprising an additional fin unit located on the fin unit, the additional fin unit comprising a plurality of parallel fins with a plurality of channels defined therebetween, each fin of the additional fin unit comprising a main plate perpendicular to the base and two flanges bent from edges of the main plate, the main plate of the each fin of the additional fin unit comprising an inlet section, an outlet section and a neck section interconnecting the inlet and outlet sections of the each fin of the additional fin unit, a height of the neck section of the each fin of the additional fin unit reducing gradually from the inlet section to the outlet section of the each fin of the additional fin unit.
 6. The heat dissipation device as claimed in claim 5, wherein the inlet sections of the additional fin unit are attached to the inlet sections of the fin unit, the neck sections and the outlet sections of the additional fin unit and the fin unit are spaced from each other.
 7. The heat dissipation device as claimed in claim 6, wherein the outlet sections of the additional fin unit and the fin unit are parallel to each other, and a distance between the neck sections of the additional fin unit and the fin unit increases gradually from the inlet sections to the outlet sections.
 8. The heat dissipation device as claimed in claim 7, further comprising two heat pipes connecting the base, the fin unit and the additional fin unit.
 9. The heat dissipation device as claimed in claim 8, wherein the heat pipes are U-shaped and each comprise an evaporating portion connecting to the base, a condensing portion and a middle portion interconnecting the evaporating portion and the condensing portion, the condensing portion of each heat pipe inserting into a corresponding one of the fin unit and the additional fin unit.
 10. The heat dissipation device as claimed in claim 9, wherein two grooves are defined in the base, the evaporating portions of the heat pipes being received in the two grooves, and a hole is defined in each of the outlet sections of the fins of the fin unit and the additional fin unit, the condensing portions of the heat pipes being inserted in the holes, respectively.
 11. The heat dissipation device as claimed in claim 10, wherein the evaporating portion of one of the heat pipes is attached to a bottom of the inlet sections of the fin unit, and the condensing portion of the one of the heat pipes inserts into the outlet sections of the additional fin unit.
 12. The heat dissipation device as claimed in claim 5, wherein each of the main plates of the additional fin unit further comprises a bent section extending downwardly from a free end of the outlet section of the each of the main plates of the additional fin unit.
 13. A heat dissipation device comprising: a base; a first fin unit and a second fin unit, the first fin unit located on the base, the second fin unit located on the first fin unit, each of the first and second fin units comprising a plurality of parallel fins with a plurality of channels defined therebetween, each fin comprising an inlet section, an outlet section and a neck section interconnecting the inlet and outlet sections, a height of the inlet section being larger than that of the outlet section, a height of the neck section reducing gradually from the inlet section to the outlet section; two heat pipes each comprising an evaporating portion connecting with the base, and a condensing portion inserting into a corresponding one of the outlet sections of the first and second fin units; and a fan located above the base and mounted to the inlet sections of the first and second fin units.
 14. The heat dissipation device as claimed in claim 13, wherein each fin of the first and second fin units further comprises a bent section extending downwardly from a free end of the outlet section thereof.
 15. The heat dissipation device as claimed in claim 13, wherein the inlet sections of the first fin unit are attached to the base, the neck sections and outlet sections of the first fin unit are spaced from the base.
 16. The heat dissipation device as claimed in claim 13, wherein the inlet sections of the second fin unit are attached to the inlet sections of the first fin unit, and the neck sections and outlet sections of the first and second fin units are spaced from each other.
 17. The heat dissipation device as claimed in claim 16, wherein the outlet sections of the first and second fin units are parallel to each other, and a distance between the neck sections of the first and second fin units increases gradually from the inlet sections to the outlet sections.
 18. The heat dissipation device as claimed in claim 13, wherein the evaporating portion of one of the heat pipes is attached to a bottom of the inlet sections of the first fin unit, and the condensing portion of the one of the heat pipes inserts into the outlet sections of the second fin unit.
 19. A heat dissipation device comprising: a base; at least one fin unit arranged on the base and comprising a plurality of fins perpendicular to the base, with a plurality of channels defined therebetween, each fin comprising an inlet section, an outlet section, a neck section interconnecting the inlet and outlet sections, and a bent section extending downwardly from a free end of the outlet section, a height of the neck section reducing gradually from the inlet section to the outlet section; at least one heat pipe comprising an evaporating portion connecting with the base and a condensing portion inserting into the outlet sections of the fins; and a fan located on the base and mounted onto the inlet sections of the fins, cooling air generated by the fan flowing into the channels of the at least one fin unit via the inlet sections of the fins, speeding up at the neck sections, and consequently accelerating to flow out from the channels via the outlet sections and the bent sections of the fins.
 20. The heat dissipation device as claimed in claim 19, wherein the inlet sections of the at least one fin unit are attached to the base, the neck sections, the outlet sections and the bent sections of the at least one fin unit are spaced from the base. 